2/ "As you do the lunge, focus on moving your torso only up and down, not pushing it forward," says Craig Rasmussen, a fitness coach at Results Fitness in Santa Clarita, California. This keeps your weight balanced evenly through your front foot, allowing you to press into the floor with your heel, which tones more lower-body muscle.

1/ As you squat, imagine you're sitting down into a chair, rather than forward on top of your knees. Push your hips back first instead of beginning by bending your knees, which puts more stress on your joints, says Dan John, a strength coach in Burlingame, California.

2/ Women tend to lean forward on their toes, but they should sit back into their heels. Try this fix: Pretend that you're standing on a paper towel, says Charlie Weingroff, lead physical therapist for the U.S. Marine Corps Special Operations Command at Camp Lejeune, North Carolina. "Then imagine trying to rip the towel apart by pressing your feet onto the floor and outward." This activates your glutes, which helps you use heavier weights and break through plateaus.

1/ "When bending down, act as if you are holding a tray of drinks and need to close the door behind you with your backside," says Alwyn Cosgrove, co-owner of Results Fitness. This helps you push your hips back instead of rounding your lower back—a form blunder that puts you at risk for back problems.

2/ It's easy to put too much space between the weight and your body as you move up and down. Pretend you're shaving your legs with the bar or dumbbells, suggests Kaitlyn Weiss, a certified strength and conditioning specialist in Southern California. The farther the weights are from your body, the more strain on your back, which limits the work of your hamstrings and glutes.

What You Do Wrong:
You ignore the muscles that draw back your shoulder blades.

1/ "Before you start the exercise, create as much space as you can between your ears and shoulders," says Rasmussen. Pull your shoulder blades down and back, which will ensure you work the intended middle- and upper-back muscles.

2/ "As you row the weights, stick out your chest," says Mike Boyle, owner of Mike Boyle Strength and Conditioning in Woburn, Massachusetts. This allows you to better retract your shoulder blades, which will lead to better results.

3/ "Imagine an orange between your shoulder blades," says Nick Grantham, owner of Smart Fitness in the U.K. "As you pull the weights or your body up, 'squeeze the juice out of it' by bringing your shoulder blades together."